After a short stint in legal practice, she spent over 25 years as head of the legal departments of several multinationals including the Jurong Town Corporation, the Jardine Matheson (South East Asia) Group and the Singapore Airlines group. She has extensive experience in general corporate and commercial law with particular focus on general aviation and airline management involving aircraft sales, purchases and leases in Singapore.

Doreen is presently a Consultant of the Firm and was admitted to the Singapore Bar in 1966.